Best Wood Glues

Buying guide for Best wood glues

You’ve got two pieces of wood to put together. You can nail them, screw them, or glue them. The big advantage of wood glue is that, used properly, the join is invisible and won’t detract from the finished piece, which is generally considered a mark of quality. Sometimes you have small pieces of wood to join, and then it’s not so much about quality but that a screw or nail might simply be too big. 

There are other considerations, too. Screws and nails rust, weakening them and leaving unsightly streaks on your woodwork. Screws and nails don’t “give” like wood does, so they can work loose as the wood expands and contracts.

Given the variety of jobs wood glues need to do, it’s no surprise there are many different types. Some are quite versatile, but others are not, so it’s important to know which is best for a particular task. 

Screws are an easy and strong way to join wood, but you don’t want the screwheads showing on quality woodwork. If you sink the heads under the surface, you can glue a small wooden plug on top, matching the direction of the grain. Once sanded and finished, the plugs are almost invisible.

Key considerations

Types of wood glue

Hide glue, made from the collagen found in animal skins, is probably the oldest wood glue around. The fact that there’s furniture that was put together with hide glue hundreds of years ago is a testament to how well it works. 

Unfortunately, it’s difficult to work with. It needs to be kept warm and frequently diluted to keep it from drying out. Urea-formaldehyde was added to mitigate this, but it is now recognized as carcinogenic. Modern, safe hide glues are available, and luthiers, piano makers, and furniture restorers might use them, but they are no longer popular.

Polyvinyl acetate wood glue (PVA) is probably the most widely recognized today. Many people have used it since they were kids because it’s non-toxic and works well with paper and cardboard. It’s cheap and water-soluble so cleanup is easy.

PVA wood glue is great for wood-to-wood joints, but any glue that squeezes out needs to be cleaned up quickly because once it’s dry it can’t be stained or painted. And because it soaks into the grain if left on the wood, it’s almost impossible to remove, too. PVA wood glue also isn’t great at joining end grain because it tends to soak in too much. And it’s not good for joining wood to materials like glass, ceramic, or stone. Plus it’s for interior use only.

Aliphatic resin (carpenter’s glue) is a variation of PVA. Normally, PVA is white and aliphatic resin is yellow. It has many of the same virtues as PVA — nontoxic, easy to use, and water-soluble — but it’s stronger and can be sanded. Some versions are waterproof and can be used outdoors.

Polyurethane wood glue was initially seen as a wonder glue when it was first available. Unlike PVA, it’s good with end grain and a wide variety of other materials. When dry, it can be sawn, chiseled, sanded, and painted or stained with solvent-based products. It’s entirely waterproof, so it’s good outdoors, too. For versatility, it’s hard to beat, and it’s useful to have around the home; however, pro woodworkers tend to prefer aliphatic resin.

The downsides to polyurethane wood glue are that it’s toxic, it can irritate the skin, the fumes can be unpleasant, and it’s not water-soluble, so cleanup requires solvents. It also foams up when used, which can be useful for filling small gaps, but it means you have to be careful when clamping or the joints may not meet properly.

Epoxy glue — two-part glue that comes as resin and hardener — strictly speaking isn’t wood glue, but it does have its uses. It’s very good at filling gaps when wood has been damaged, and it can allow glued surfaces to be redrilled and screwed. It’s generally waterproof, and some epoxy glues are specifically formulated for boat builders.

Epoxy glue can be good at joining multiple materials, but it’s not always successful. Proportions — usually 1:1 — need to be accurate or the joints have a tendency to fail over time. It’s expensive to use on anything but modest-sized repairs. It takes a long time to cure, particularly when used as a filler. Like polyurethane wood glue, it’s always good to have some in the house, but it’s best used for patch repairs, not full-scale woodworking.

Cyanoacrylates (super glues and gel glues) are worth checking out because they’re handy for small repairs. These glues can stick both porous and nonporous items together. They’re particularly good with skin, so be careful!

However, standard super glue can be too thin for joining wood, and it can dry on the surface before you get a chance to put the two pieces together. Gel versions are easier to use but still provide a more or less instant bond (5 to 15 seconds to fix and only around a minute for full cure). 

If you’re repairing period furniture and you want to be authentic, you need to use hide glue. It used to require constant warming — a pot would sit on a stove all day. Fortunately, modern versions are easier to work with.

Accessories

Spreader: Sili Wood Glue Applicator Set
Your index fingers make great glue applicators, but that gets kind of messy. This kit offers two sizes of brush, a multipurpose spreader, and a useful glue tray. They’re all silicone, so they wash off easily or can be left to dry and the waste glue just peels off.

Gloves: KAYGO Safety Work Gloves
Few wood glues are irritating to the skin, but they can stick to your hands just as effectively as they do to the wood and are a real pain to remove. These gloves are breathable so your hands stay comfortable. They are strong enough to be durable without losing the dexterity you need.

Wood glue prices

Inexpensive: You can often find cheap PVA wood glue in budget stores, and at a couple of bucks for a 16-ounce bottle it can look like a bargain. They typically include chalk and other fillers that weaken the glue considerably. In fact, most cheap, unbranded glues are not worth the trouble.

Mid-range: Quality super glues are about $5 or $6 a tube. PVA glue costs from around $10 to $15 a quart. Polyurethanes start at around the same price.

Expensive: While no wood glue is particularly expensive when you consider their coverage and permanence, high-strength waterproof polyurethane can be $15 for an 8-ounce tube, which is twice the price of PVA. It is considerably more versatile, though.

Be careful with glue squeezing out of joints. Some glues can be stained or painted, but others cannot, and they might leave unsightly pale streaks in your finish.

Tips

• Always read the instructions. Do this even if you’ve used a similar product before. Formulations change frequently, so don’t assume you know what to do. And run a dry assembly first to work out the optimum order of putting parts together.
• Assemble everything you need first. Work out the clamps you need. Make sure they’re open wide enough so you can fit them over the components easily but not so wide you waste time winding or sliding them in. Lay them out where you can get to them easily. There’s an old woodworker’s adage that you can never have too many clamps, and it’s still true today! Have the materials for cleaning up spills easily available, too.
• Note the glue’s “open time.” All glues have an open time — the period they remain workable. With super glues and quick-set epoxies, you have to work very quickly, although it’s not usually a problem with small repairs. When you’re assembling a large piece of furniture, you might have to glue a number of components at the same time. While open times for PVA and polyurethane are reasonable — anywhere from 5 to 30 minutes — you still want to work as quickly as possible.
• Glue small sections if you can. With complex pieces, it’s better to glue and clamp small sections, if practical, rather than doing the whole thing at once. If the glue starts to drip from pieces that are waiting, things can get messy fast.
• Use one thin coat on each surface to be joined. It’s easier to control spread, and you’ll squeeze less glue out, reducing cleanup.
• Make any adjustments before the glue sets. When you’ve finished a piece, check that it’s all put together properly and that things are level and square. You’ve probably got time to loosen a clamp and make small adjustments now. In an hour it could be too late.
• Check the cure time. Although a glue might be set enough in an hour or two that you can’t get the joint apart, some movement may be possible for 24 hours or more. Don’t remove the clamps until the glue is fully cured.

Cyanoacrylates — super glues — are brilliant at gluing skin, as you may have discovered! Wearing gloves is recommended, but if you do have a spill, pure acetone is good for cleanups.

FAQ

Q. Do I always need to clamp the pieces while wood glue sets?

A. Cyanoacrylates (super glues) are virtually instant, as are some rapid gel glues. Quick-set epoxies are very fast but still require minimal clamping, unless you want to hold them for several minutes! However, while these glues are good for small repairs, they are not good for jobs like furniture assembly. PVAs and polyurethanes need a tight fit, so clamping is important. Also, there’s a risk that the foaming action of polyurethane can push joints apart if they aren’t secured properly.

Q. How safe are wood glues?

A. With an increased focus on water-based glues, many are safer than ever. However, some contain formaldehyde, and other toxins may be present. Always check the label and follow the manufacturer’s advice. Contact with skin won’t normally present problems, though it depends on your sensitivity. Even nontoxic formulas can be difficult to remove, which is why you should always wear gloves. As with any chemical, avoid getting the glue in your eyes (safety glasses are always a good idea when working in the shop anyway), and keep the glue out of reach of children.

Q. How long will wood glue last once opened?

A. The shelf life of wood glues varies enormously, and super glues seem to go off before you’ve put the lid back on the tube! Anything that’s in a sealed container will usually last a reasonable length of time, though the air that gets in may cause a skin to form on glues like PVA. It can usually be removed and the remainder used normally. Many glues will last a couple of years, but the only way to be sure is to check the manufacturer’s details, though it’s not unusual for them to be optimistic! If you’re a regular woodworker, it’s not usually a problem. If you’re selecting wood glue for a specific job, it makes sense to get only as much as you need rather than having some left over “just in case.”